A variety of types of truck covering assemblies are used with trailers, truck beds, dump trucks, or other transport vehicles. The primary reason for a tarp cover assembly is to either prevent the load from escaping or to protect the load from the elements. The type of covering assembly used generally depends upon the geometry of the trailer, truck bed, dump truck or transport vehicle. Usually these covering assemblies are bulky and awkward to manually operate. For those reasons a variety of motor assemblies have been used to allow for easier operation of the covering systems.
Such motor assemblies used with truck covering assemblies in the past have been controlled by momentary switches which require the operator to visually examine the position of the cover while it is moving from either the fully covered position to the fully uncovered position or from the fully uncovered position to the fully covered position and released the switch when the cover reaches the desired position. The visual examination by the operator is burdensome and undesirable. Additionally, one common type of truck covering assembly comprises of a bail assembly that is pivotally mounted with a cover support section connected to one end of the cover and is spring biased so as to extend the cover over the open container. This type of covering assembly requires a large motor assembly to overcome the spring bias of the bail assembly in the movement from the covered position to the uncovered position. Furthermore, such motor assemblies are subjected to the harsh outdoor environment and prone to failure of electrical components or getting struck and damaged. U.S. Pat. No. 5,829,819 describes a novel friction disc brake arrangement that is actuated by an electric circuit in conjunction with the drive motor for automatic braking the truck covering motor when the electric motor is turned off.